This invention relates to solenoid devices and more particularly to an improved tractive solenoid device having a double acting plunger activated by momentary electrical signals to initiate and latch two predetermined push-pull camming operations.
When tractive solenoids are used in certain applications as a controlled actuating device, certain design considerations become critical including a compact size, minimum weight, ease of mounting, required electrical power for operation, while maintaining reliability, ease of manufacture and minimum cost. The present invention is directed to such a tractive solenoid device in which the design and construction thereof is to provide a predetermined force by a solenoid plunger which is operated in opposite directions and is to travel through a predetermined stroke length. In one contemplated application, the plunger operation of a tractive solenoid is required when used to control a clutch mechanism included in a dial gear train of a multirate dial register used in electric energy billing meters. The close relationships of a large number of shaft mounted gear trains and associated clutch mechanisms are required for driving as many as three different sets of dial indicators in a single register. These close relationships of the register parts severely limit the available space for mounting and operating a solenoid device used as an actuator in a clutch operating arrangement. Examples of prior art solenoid devices used in multirate and multi-dial registers for electric energy meters are disclosed in the above cross-referenced copending applications Ser. Nos. 167,952 and 167,953, and also in U.S. Pat. No. 4,128,807 issued Dec. 5, 1978 and assigned to the assignee of this invention. A further example of a solenoid device used in multirate meter registers is disclosed in U.S. Pat. No. 4,050,020.